Boiler shows E2 and shuts down, often linked to overheat or sensor issues on some Worcester Bosch models.

Safety first: Allow the boiler to cool completely. Do not bypass or short any safety devices.

• Check system pressure and air: Ensure pressure is 1.0–1.5 bar cold and bleed radiators to remove air. Top up pressure as needed.
• Reset overheat stat (if accessible): Some models have a manual reset button on the overheat thermostat behind the front panel. Only press it once the boiler is cool and only if you can access it without disturbing the combustion chamber.
• Check pump noise: When calling for heat, listen for the pump. If it is noisy, seized, or very hot, it may not be circulating water.
• Engineer tasks: A Gas Safe engineer should check pump performance, inspect the primary heat exchanger for scale/sludge, verify correct gas rate and combustion, and replace the overheat thermostat if faulty.